What it helps you decide
Estimate NaOH or KOH from transparent oil SAP values.
Free formulation estimate
Make the lye math transparent before you make soap.
Use common oil presets or enter supplier SAP values, then calculate NaOH or KOH, superfat, water, and an approximate formula profile.
Start with the example
The values already filled in are a working example—not a recommendation.
- 1Choose the closest starting point.
- 2Replace the example with your real details.
- 3Read the live result and its important limits.
Oil formula
Enter oils by weight
OilWeight gNaOH SAP
Caustic-chemical safety
SAP values vary by oil lot and source. Verify every value with your supplier and a second trusted calculator. Wear appropriate PPE; add lye to water—never water to lye—and follow a tested process.
About this free formulation & batching tool
How to use the Soap Lye & Superfat Calculator
Estimate NaOH or KOH from transparent oil SAP values. The calculator runs privately in your browser and is designed to make the assumptions behind the answer visible.
What to have ready
Start with a tested baseline formula, measured weights, the unit used by the full batch, and your actual finished yield or process loss.
How to use the result
Treat the output as a controlled batch draft. Record the assumptions, run a small test, and approve the result only after checking quality and safety.
Complete workflow guide
Candle, soap, and cosmetic formulation
A calculator can check the math. A reliable product also needs clear supplier information, a repeatable process, testing in the final package, and the right label for what the product is and what you claim it does.
Ready for the connected version?
Turn the calculation into a repeatable workflow.
Batch Scale connects recipes, materials, costs, inventory, production, sales, and your storefront in one workspace.